| Spray forming process has been known to the only method by which bulk materials solidified with a fairly high cooling rate of l0²-10³K/sec. This process has been reported to be applicable to production of conventional alloys as well as production of materials which need a rapid solidification processing technique because of difficulties in manufacturing. Thus, the spray forming process has attracted a considerable attention as one of the new important solidification process techniques. Among the operating conditions in spray forming process, melt flow rate and gas flow rate are the most important factors. Aspiration pressure, however, is also a very important factor determining the success of atomizing process as will as influencing the melt flow rate. In this study, the aspiration pressure was measured according to not only the gas nozzle geometry; spraying gas angle, the width of annulus gas exit and the diameter of the annulus gas exit but also operating conditions; outer and inner diameter of orifice, the geometry of orifice tip and spraying gas pressure. Thus the variation of the aspiration pressure is able to be known. On the basis of the data, we can introduce the model to estimate the possible operating region according to the relation of the gas nozzle, orifice and spraying gas condition. |
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